Processes Of Making Oral Compositions Containing Gel Networks

ABSTRACT

The present invention is directed towards a process for making oral compositions comprising gel networks. The gel networks are formed from a fatty amphiphile dispersion and swelling surfactant. The fatty amphiphile dispersion comprises one or more fatty amphiphiles, one or more dispersing surfactants, and one or more solvents. A gel network is formed when the fatty amphiphile dispersion is combined with the swelling surfactant. A method of preparing the fatty amphiphile dispersion and oral composition is included.

FIELD OF THE INVENTION

The present invention relates to an oral composition containing a gelnetwork and a process for forming the gel network.

BACKGROUND OF THE INVENTION

The rheology of oral care composition, particularly dentifrices, is verychallenging to formulate. The composition must not be too thick so itcan easily dispense out of a tube but thick enough to stand up on atoothbrush without sinking into the bristles. The viscosity of the oralcomposition must remain stable over time as not to continue to thickenso the oral composition remains easy to dispense during the shelf life.Once dispensed from a container, the oral composition should not bestringy or sticky as to be messy for a consumer to use. The oralcomposition must also easily disperse once in the mouth and create foam.It is also desired that the oral composition not stick to a sink orleave difficult to remove hard dried residue. In addition to balancingthe viscosity and shear thinning to formulate acceptable rheology, theoral composition must also be stable and keep active ingredients, suchas fluoride, available.

In addition to the above requirement for a consumer desired oralcomposition, it is also desired that oral composition be relatively easyto process. The oral composition must have the desired rheology andshelf stability as described above but also be viscous enough to quicklyfill the oral composition into a container. It is also desired that theprocess not require special equipment and that the time to process notbe long. It is also desired that the process be economical. Typically,oral compositions are thickened with polymeric thickeners. Polymericthickeners may require a hydration step which can limit processingflexibility and cause aeration problems. It is also desired that thethickening system of an oral composition be low cost and comprisecommonly available ingredients.

Based on the foregoing, there is an ongoing need for improved thickeningor structuring systems for oral compositions. There is also the need foreconomical and convenient processes in making oral compositions. None ofthe existing art provides all of the advantages and benefits of thepresent invention.

SUMMARY OF THE INVENTION

The present invention is directed to an oral composition containing agel network and a process of making the oral composition. The oralcomposition comprising the gel network is produced in a two-stepprocess. The first step of the process is to form a fatty amphiphiledispersion. The dispersion comprises one or more fatty amphiphiles,solvents, and dispersing surfactants. The fatty amphiphile is heated toa temperature sufficient to allow melting and subsequent emulsificationof the fatty amphiphile. Once the fatty amphiphile dispersion is formed,it can be quickly cooled or allowed to cool to room temperature. Asuppressing material can optionally be added to the fatty amphiphiledispersion to aid in restricting the swelling of the fatty amphiphile.The second step is forming the oral composition. The fatty amphiphiledispersion is added to the remainder of the materials in the oralcomposition and to the swelling surfactant. Once the swelling surfactantis added, a gel network is formed. The remainder of the materials in theoral composition can be added before, at the same time as, or after theswelling surfactant is added. It may be desired to add the swellingsurfactant last so that the gel network is not formed until the end ofthe process. This process enables the gel network to be formed withoutheating the swelling surfactant or oral carrier materials.

These and other features, aspects, and advantages of the presentinvention will become evident to those skilled in the art from a readingof the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

While the specification concludes with claims which particularly pointout and distinctly claim the invention, it is believed the presentinvention will be better understood from the following description.

All percentages, parts and ratios are based upon the total weight of thecompositions of the present invention, unless otherwise specified. Allsuch weights as they pertain to listed ingredients are based on theactive level and, therefore, do not include solvents or by-products thatmay be included in commercially available materials, unless otherwisespecified. The term “weight percent” may be denoted as “wt. %” herein.

All molecular weights as used herein are weight average molecularweights expressed as grams/mole, unless otherwise specified.

Herein, “comprising” means that other steps and other ingredients whichdo not affect the end result can be added. This term encompasses theterms “consisting of” and “consisting essentially of”. The compositionsand methods/processes of the present invention can comprise, consist of,and consist essentially of the essential elements and limitations of theinvention described herein, as well as any of the additional or optionalingredients, components, steps, or limitations described herein.

Herein, “effective amount” means an amount of a compound or compositionsufficient to significantly induce a positive benefit, preferably anoral health benefit, but low enough to avoid serious side effects, i.e.,to provide a reasonable benefit to risk ratio, within the sound judgmentof a skilled artisan.

By “oral composition” is meant a product, which in the ordinary courseof usage, is not intentionally swallowed for purposes of systemicadministration of particular therapeutic agents, but is rather retainedin the oral cavity for a time sufficient to contact substantially all ofthe dental surfaces and/or oral tissues for purposes of oral activity.The oral composition of the present invention may be in various formsincluding toothpaste, dentifrice, tooth gel, liquid gel, subgingivalgel, foam, mousse, cream, or denture product. The oral composition mayalso be a rinse thickened by a gel network. The oral composition mayalso be incorporated onto strips or films for direct application orattachment to oral surfaces.

The term “dentifrice”, as used herein, means paste, gel, cream, powder,or liquid formulations unless otherwise specified, used to clean thesurfaces of the oral cavity. The dentifrice composition may be a singlephase composition or may be a combination of two or more separatedentifrice compositions. The dentifrice composition may be in anydesired form, such as deep striped, surface striped, multilayered,having the gel surrounding the paste, or any combination thereof. Eachdentifrice composition in a dentifrice comprising two or more separatedentifrice compositions may be contained in a physically separatedcompartment of a dispenser and dispensed side-by-side.

The term “dispenser”, as used herein, means any pump, tube, package, orcontainer suitable for dispensing oral compositions.

The term “teeth”, as used herein, refers to natural teeth as well asartificial teeth or dental prosthesis.

The term “polymer” as used herein shall include materials whether madeby polymerization of one type of monomer or made by two (i.e.,copolymers) or more types of monomers.

The term “water soluble” as used herein means that the material issoluble in water in the present composition. In general, the materialshould be soluble at 25° C. at a concentration of 0.1% by weight of thewater solvent, preferably at 1%, more preferably at 5%, and morepreferably at 15% or greater.

The term “surfactant” as used herein means a surfactant other than afatty amphiphile. Various types of suitable surfactants are listedbelow. There are fatty amphiphile dispersing surfactants and swellingsurfactants. There will be at least one fatty amphiphile dispersingsurfactant and at least one swelling surfactant in the gel network.There may be additional surfactant in the oral composition.

The oral compositions of the present invention are formed in a two-stepprocess. The first step is to make the fatty amphiphile dispersion. Thedispersion comprises one or more fatty amphiphiles, solvents, and fattyamphiphile dispersing surfactants. The fatty amphiphile is heated toallow formation of the dispersion. Once formed, the dispersion ispreferably cooled prior to combining with the other materials. Once theswelling surfactant is added to the fatty amphiphile dispersion, a gelnetwork is formed. The oral carrier materials are typically addedbefore, with, or after the swelling surfactant is added. It may bedesired to add the swelling surfactant after the majority of the oralcarrier materials so that the oral composition does not build viscosityuntil the end of the making process. The resultant oral compositioncomprises a dispersed gel network phase and an oral carrier phase. Tothe naked eye, the dispersed gel network phase and the oral carrierphase cannot be distinguished. The phases are immiscible within eachother. Each of the essential components, as well as preferred oroptional components, is described in detail hereinafter.

A. Fatty Amphiphile Dispersion and Gel Network

The resulting oral compositions of the present invention comprise adispersed gel network phase comprising a fatty amphiphile. As usedherein, the term “gel network” refers to a lamellar or vesicular solidcrystalline phase which comprises at least one fatty amphiphile asspecified below, at least one swelling surfactant as specified below,and a solvent as specified below. The lamellar or vesicular phasecomprises bi-layers made up of a first layer comprising the fattyamphiphile and the swelling surfactant and alternating with a secondlayer comprising the solvent. For the lamellar crystalline phase toform, the fatty amphiphile and swelling surfactant must be dispersedwithin the solvent. The term “solid crystalline”, as used herein, refersto the structure of the lamellar or vesicular phase which forms at atemperature below the chain melt temperature of the layer in the gelnetwork comprising the one or more fatty amphiphiles. The chain melttemperature may be measured by differential scanning calorimetry, amethod of which is described in the Examples below.

The gel network in the oral composition can be used to structure theoral composition. The structuring provided by the gel network providesthe desired rheology or viscosity by thickening the oral composition.The structuring can be done without the need for polymeric thickeningagents, however, polymeric thickeners or other agents could be used inaddition to the gel network to structure the oral composition.

Gel networks, generally, are further described by G. M. Eccleston,“Functions of Mixed Emulsifiers and Emulsifying Waxes in DermatologicalLotions and Creams”, Colloids and Surfaces A: Physiochem. and Eng.Aspects 123-124 (1997) 169-182; and by G. M Eccleston, “TheMicrostructure of Semisolid Creams”, Pharmacy International, Vol. 7,63-70 (1986).

According to this embodiment of the present invention, the gel networkof the present invention is prepared in a two-step process. The firststep is forming a fatty amphiphile dispersion. The fatty amphiphiledispersion comprises a fatty amphiphile, a dispersing surfactant, and asolvent. It is desired that the swelling of the fatty amphiphile becontrolled (reduced) in the dispersion to help keep the viscosity of thedispersion low. The viscosity of the fatty amphiphile dispersion shouldbe below 200 BKU. Preferably, the fatty amphiphile dispersion will shearthin easily as measured by the yield value. The dispersion may have ahigher viscosity if it is able to yield value to be able to be pumped.Not being bound by theory, it is believed that the fatty amphiphiledispersion is structured by particle-particle interaction and internalphase packing. The fatty amphiphile is heated to a level in the range ofabout 50° C. to about 90° C. The dispersing surfactant and solvent areadded to the melted fatty amphiphile to form the fatty amphiphiledispersion. This dispersion may cool to a level in the range of about20° C. to about 35° C. by, for example, passing the mixture through aheat exchanger. Other methods of allowing the dispersion to cool includecooling jackets, mixing, or additional time in which the dispersion isallowed to slowly come to room temperature. Alternatively, additionalmaterials at a cooler temperature may be added to the dispersion whichwill aid in cooling the dispersion. It is not required that the fattyamphiphile dispersion be cooled but it may be advantageous inprocessing. A milling step may also occur when making the fattyamphiphile dispersion. If desired, cooling and milling can occursimultaneously.

The fatty amphiphile and the fatty amphiphile dispersing surfactant andsolvent form a fatty amphiphile dispersion with limited swelling. Thefatty amphiphile dispersion is then added to the remainder of the oralcomposition materials and the swelling surfactant which enables thefatty amphiphile and swelling surfactant to form a stable gel network.It is desired to maximize the fatty alcohol swelling in this step whenthe gel network is formed. The oral composition materials can be addedat any time during the process.

Alternative methods or additional means of preparing the dispersioninclude sonication and/or milling of the fatty amphiphile, the fattyamphiphile dispersing surfactant, and/or solvent, while these componentsare heated, to reduce the particle size of the melted fatty amphiphilephase. This results in an increase in surface area of the fattyamphiphile dispersion. Also, the sonication and/or milling of the formedfatty amphiphile dispersion with the swelling surfactant to swell thefatty amphiphile may be desired to aid in forming the gel network.

An equilibrated lamellar dispersion (“ELD”) is formed in the final oralcomposition. The ELD is a dispersed lamellar or vesicular phaseresulting from the gel network component substantially equilibratingwith oral carriers and other optional components.

The presence of the gel network in the oral composition in the form ofthe ELD can be confirmed by means known to one skilled in the art, suchas X-ray analysis, optical microscopy, electron microscopy, anddifferential scanning calorimetry. Methods of X-ray analysis anddifferential scanning calorimetry are described in the Examples below.

In an embodiment of the present invention, the weight ratio of the fattyamphiphile to the swelling surfactant in the gel network component isgreater than about 1:5, preferably from about 1:3 to about 100:1, morepreferably greater than about 1:1 to about 20:1, and even morepreferably greater than about 2:1 to about 10:1.

1. Fatty Amphiphile

The gel network component of the present invention comprises at leastone fatty amphiphile. As used herein, “fatty amphiphile” refers to acompound having a hydrophobic tail group of R₁ as defined below and ahydrophilic head group which does not make the compound water soluble(immiscible), wherein the compound also has a net neutral charge at thepH of the oral composition. The term “water soluble”, as used herein,means that the material is soluble in water in the present composition.In general, the material should be soluble at 25° C. at a concentrationof 0.1% by weight of the water solvent, preferably at 1%, morepreferably at 5%, more preferably at 15%.

The fatty amphiphile of the present invention may be characterized as acompound having a Hydrophilic-Lipophilic Balance (“HLB”) of 6 or less.The HLB, as used herein, is the standard HLB according to Griffin, J.Soc. Cosm. Chem., vol. 5, 249 (1954). If using a mixture of fattyamphiphiles, it is desired that the mixture have a HLB of from about 1to about 6 and preferably from about 1 to about 3. Therefore, fattyamphiphile having an HLB above 6 can be used if it is mixed with anotherfatty amphiphile having a lower HLB. In forming the fatty amphiphiledispersion, a low HLB is desired so that a lamellar phase does not formwith the dispersing surfactant. The lower HLB means that the fattyamphiphiles will not be soluble in the solvent and reduced swelling ofthe fatty amphiphiles.

The oral compositions of the present invention comprise fatty amphiphilein an amount from about 0.05% to about 30%, preferably from about 0.1%to about 20%, and more preferably from about 0.5% to about 10%, byweight of the final oral composition. In some examples, the amount offatty amphiphile in the final oral composition is from about 2% to about8% and more preferably from about 4% to about 6%. Based on the amount offatty amphiphile in the final oral composition, it can then bedetermined how much fatty amphiphile is added to the fatty amphiphiledispersion and how much of the fatty amphiphile dispersion is added tothe final oral composition. Typically, the fatty amphiphile is presentin an amount of from about 5% to about 80% and preferably from about 15%to about 60% in the fatty amphiphile dispersion. In some examples, theamount of fatty amphiphile in the fatty amphiphile dispersion is fromabout 30% to about 55%. The amount of fatty amphiphile will be chosenbased on the formation of the gel network and the composition of theoral formulation. For example, an oral composition containing lowamounts of water may require about 1% of a fatty amphiphile whereas anoral composition with higher amounts of water may require 6% or more ofa fatty amphiphile.

According to the present invention, suitable fatty amphiphiles, orsuitable mixtures of two or more fatty amphiphiles, preferably have amelting point of at least about 40° C. In some embodiments, it ispreferred that the melting point be at least about 50° C. or greaterthan about 55° C. or greater than about 60° C. The melting point, asused herein, may be measured by a standard melting point method asdescribed in U.S. Pharmacopeia, USP-NF General Chapter <741> “Meltingrange or temperature”. The melting point of a mixture of two or morematerials is determined by mixing the two or more materials at atemperature above the respective melt points and then allowing themixture to cool. If the resulting composite is a homogeneous solid belowabout 45° C., then the mixture has a suitable melting point for use inthe present invention. A mixture of two or more fatty amphiphiles,wherein the mixture comprises at least one fatty amphiphile having anindividual melting point of less than about 45° C., still is suitablefor use in the present invention provided that the composite meltingpoint of the mixture is at least about 45° C.

According to the present invention, suitable fatty amphiphiles have ahydrophobic tail group of R₁. As used herein, R₁ is an alkyl, alkenyl(containing up to 3 double bonds), alkyl aromatic, or branched alkylgroup of C₁₂-C₇₀ length. Non-limiting examples of alkyl, alkenyl, orbranched alkyl groups suitable for the fatty amphiphiles of the presentinvention include lauryl, tridecyl, myristyl, pentadecyl, cetyl,heptadecyl, stearyl, arachidyl, behenyl, undecylenyl, palmitoleyl,oleyl, palmoleyl, linoleyl, linolenyl, arahchidonyl, elaidyl,elaeostearyl, erucyl, isolauryl, isotridecyl, isomyristal,isopentadecyl, petroselinyl, isocetyl, isoheptadecyl, isostearyl,isoarachidyl, isobehnyl, gadoleyl, brassidyl, and technical-grademixture thereof.

As used herein, R₁ also may be a branched alkyl group prepared byalkaline condensation of alcohols to give higher molecular weight,branched isoalcohols. These branched isoalcohols are referred to in theart as Guerbet alcohols.

R₁ may be alkyl, alkenyl or branched carbon chains of vegetable origin,such as wheat germ, sunflower, grape seed, sesame, maize, apricot,castor, avocado, olive, soybean, sweet almond, palm, rapeseed, cottonseed, hazelnut, macadamia, karite, jojoba, alfalfa, poppy, pumpkinseed,sesame, cucumber, blackcurrant, evening primrose, millet, barley,quinoa, rye, safflower, candlenut, passion flower or musk rose oil, andkarite butter.

Suitable fatty amphiphiles of the present invention also have ahydrophilic head group which does not make the compound water soluble,such as in compounds having an HLB of 6 or less. Non-limiting examplesof classes of compounds having such a hydrophilic head group includefatty alcohols, alkoxylated fatty alcohols, fatty phenols, alkoxylatedfatty phenols, fatty amides, alkyoxylated fatty amides, fatty amines,fatty alkylamidoalkylamines, fatty alkyoxyalted amines, fattycarbamates, fatty amine oxides, fatty acids, alkoxylated fatty acids,fatty diesters, fatty sorbitan esters, fatty sugar esters, methylglucoside esters, fatty glycol esters, mono, di & tri glycerides,polyglycerine fatty esters, alkyl glyceryl ethers, propylene glycolfatty acid esters, cholesterol, ceramides, fatty silicone waxes, fattyglucose amides, and phospholipids.

To form the gel network component of the present invention, individualfatty amphiphile compounds or combinations of two or more differentfatty amphiphile compounds may be selected. The following providesnon-limiting examples of classes of compounds from which one or morefatty amphiphiles suitable for use in the present invention may beselected.

a. Fatty Alcohols/Alkoxylated Fatty Alcohol Ethers

Fatty amphiphiles of the present invention may be selected from fattyalcohol compounds or alkoxylated fatty alcohol ether compounds accordingto the following formula:

R₁—(OR₂)_(k)—OH

wherein R₁ is as described above; R₂ is a C₁-C₅ carbon chain which maybe branched or hydroxy substituted; and k is a number ranging from about0 to about 5.

The fatty alcohols useful herein are those having from about 12 to about60 carbon atoms, preferably from about 16 to about 60 carbon atoms.These fatty alcohols may be straight or branched chain alcohols and maybe saturated or unsaturated. Non-limiting examples of suitable fattyalcohols include cetyl alcohol, stearyl alcohol, arachidyl alcohol,behenyl alcohol, eicosyl alcohol, C20-40 alcohols, C30-50 alcohols,C40-60 alcohols, and mixtures thereof.

Suitable alkoxylated fatty alcohol ethers include addition products of 1to 5 mol of ethylene oxide with a linear fatty alcohol having about 12to about 60 carbon atoms, which are all adducts obtainable by the knownindustrial oxyethylation processes. Also suitable are the polyethyleneoxide condensates of alkyl phenols, for example, the condensationproducts of alkyl phenols having an alkyl group containing from about 12to about 60 carbon atoms in either a straight chain or branched chainconfiguration, with ethylene oxide, wherein the ethylene oxide ispresent in amounts equal to from about 1 to about 5 moles of ethyleneoxide per mole of alkyl phenol. Further suitable alkoxylated fattyalcohol ethers include those derived from the condensation of ethyleneoxide with the product resulting from the reaction of propylene oxideand ethylene diamine products.

Non-limiting examples of suitable alkoxylated fatty alcohol ethersinclude steareth-2, beheneth-2, beheneth-5, beheneth-10, C20-40Pareth-3, C20-40 Pareth-10, C30-50 Pareth-3, and C30-50-Pareth-10.

In one embodiment, a combination of fatty alcohols such as cetyl andstearyl alcohol is preferred. The ratio of cetyl to stearyl alcohol canbe from about 4:1 to about 1:4, preferably from about 2:1 to about 1:2,and in some embodiments 1:1.

b. Other Fatty Amphiphiles

Fatty amphiphiles of the present invention may be selected from di-fattyethers, fatty amides including fatty alkanolamides and fatty alkoxylatedamides, fatty carbamates, fatty alkylamido alkylamines, fatty aminesincluding fatty alkanolamines and fatty alkoxylated amines, fatty amineoxides, fatty acids or alkoxylated fatty acids, fatty esters, fattyphosphorus compounds fatty sorbitan derivatives, sucrose polyesters,alkyl sulfoxides, and combinations thereof.

2. Fatty Amphiphile Dispersing Surfactant

The fatty amphiphile dispersing surfactant is chosen depending upon thefatty amphiphiles utilized. The dispersing surfactant must be watersoluble or soluble in the solvent chosen. The dispersing surfactant isadded to emulsify or disperse the fatty amphiphiles but not inducelamellar phase formation. The dispersing surfactant should effectivelyreduce surface tension and/or sterically stabilize the dispersion byphysically separating particles. Suitable dispersing surfactants shouldhave a molecular weight of at least about 500 Daltons. The molecularweight should not exceed 130 kiloDaltons or the viscosity of the fattyamphiphile dispersion would be too high. Suitable dispersing surfactantsinclude many non-alkoxylated, water-soluble polymers such as alkylatedpolyvinylpyrrolidone, such as buylated polyvinylpyrrolidonecommercialized as “Ganex P904” by ISP Corp.; mono alkyl esters ofpoly(methyl vinyl ether/maleic acid) soldium salt, includingmonobutylester of poly(methyl vinyl maleic acid sodium salt) such asincluded in the product commercialized as “Easy-Sperse” by ISP Corp.;isobuylene/ethylmadleimide/hydroxyethyl copolymer, such as included inthe product commercialized as “Aquafix FX64” by ISP Corp.;(3-dimethylaminopropyl)-methacrylamide/3-methacryloylamidopropyl-lauryl-dimthyl-ammoniiumchloride, such as included in the product commercialized as “StylezeW20” by ISP Corp. Dispersing surfactants include hydrophobicallymodified polymers. The hydrophobically modified polymers will typicallywork by sterically stabilizing the dispersion and physically separatingthe particles. Suitable hydrophobically modified polymers include cetylhydroxyl ethyl cellulose such as Natrosol Plus commercialized byHercules and inulin laryl carbamide such as Inutec SP1 commercialized byOrafti Bio Based Chemicals. The preferred dispersing surfactants shouldhave excellent safety data for oral composition usage. The fattyamphiphile dispersing surfactant is typically present in the fattyamphiphile dispersion in an amount of from about 0.01% to about 15%,preferably from about 0.05% to about 5% and commonly at about 0.1% toabout 2%. The amount of dispersing surfactant in the final oralcomposition is typically dependant upon the amount of fatty amphiphilein the dispersion and the desired amount of fatty amphiphile in thefinal composition. Typically, the dispersing surfactant will be presentin the final oral composition in an amount of from about 0.001% to about5%, commonly from about 0.01 to about 2% and from about 0.1 to about 1%by weight of the final oral composition. Preferred dispersingsurfactants include cetyl hydroxyl ethyl cellulose, inulin larylcarbamide, and buylated polyvinylpyrrolidone, mono butyl ester ofpoly(methyl vinyl maleic acid sodium salt) and combinations thereof.

3. Solvents

The fatty amphiphile dispersion of the present invention also comprisessolvents, such as water or other suitable solvents. The solventconcentration in the fatty amphiphile dispersion must be controlled asif too high of a concentration is present, swelling and/or formation ofthe lamellar phase can occur. It is not desired to form lamellar phasesin the fatty amphiphile dispersion and it is desired to limit the amountof swelling to keep the viscosity low.

A solvent is also typically present in the final oral composition. It istypically added with the swelling surfactant. The swelling surfactantand additional solvent together can contribute to the swelling of thefatty amphiphile. This, in turn, leads to the formation and thestability of the gel network. In addition to forming the gel network,the solvent can help to keep the dentifrice composition from hardeningupon exposure to air and provide a moist feel in the mouth. The solvent,as used herein, refers to suitable solvents which can be used in theplace of, or in combination with, water in the formation of the gelnetwork of the present invention.

Suitable solvents to be used in the fatty amphiphile dispersion and thefinal oral composition for the present invention include water, ediblepolyhydric alcohols such as glycerin, diglycerin, triglycerin, sorbitol,xylitol, butylene glycol, erythritol, polyethylene glycol, propyleneglycol, and combinations thereof. Sorbitol, glycerin, water, andcombinations thereof are preferred solvents. Water may be requireddepending upon the specific fatty amphiphile chosen. For low waterformulas, water may not be the solvent used in forming the fattyamphiphile dispersion as the water may be better used in other parts ofthe formula. The solvent is typically present in the fatty amphiphiledispersion in an amount of from about 0.05% to about 85%, typically fromabout 15% to about 80%, and commonly from about 35% to about 80% byweight of the fatty amphiphile dispersion. In some embodiments, thesolvent is present in an amount of from about 40% to about 65% by weightof the fatty amphiphile dispersion.

The oral compositions of the present invention comprise solvents as partof the gel network phase in an amount suitable to achieve a gel networkwhen combined with fatty amphiphile and swelling surfactant according tothe present invention. In a preferred embodiment, the oral compositionsof the present invention comprise as part of the gel network phase atleast about 0.05% of a solvent, by weight of the oral composition. Thesolvent may be present in the oral composition in amount of from about0.1% to about 99%, from about 0.5% to about 95%, and from about 1% toabout 90%.

4. Suppressing Materials

It may be desired to add a suppressing material to the fatty amphiphiledispersion. The function of the suppressing agent is to suppress theswelling of the fatty amphiphile while it is in the dispersion andbefore it is mixed with the swelling surfactant. The suppressingmaterial will help keep the viscosity low and help to prevent lamellarphase formulation. Suppressing materials include any material that helpscontrol swelling of the fatty amphiphile. Specific materials includesoluble and insoluble polar materials with dialetric constants of fromabout 6 to about 20 and typically from about 6 to about 13. Suitablematerials include polar oils such as flavor oils, and coolants, salts,and combinations thereof. The suppressing material is optionally addedto the fatty amphiphile dispersion. The suppressing material can beadded in an amount of from about 0% to about 10%, commonly from about0.1% to about 8%, and from about 1% to about 5% by weight of the finaloral composition.

5. Swelling Surfactant

The gel network component of the present invention also comprises aswelling surfactant. As used herein, “swelling surfactant” refers to oneor more surfactants which are combined with the fatty amphiphiledispersion to form the gel network of the present invention. Theswelling surfactant is not intended to be present in the pre-made fattyamphiphile dispersion and it may be desired to have the fatty amphiphiledispersion be essentially free of swelling surfactants. The swellingsurfactant is typically water soluble or miscible in the solvent or oralcarrier. The swelling surfactant may be characterized as a compoundhaving a Hydrophilic-Lipophilic Balance (“HLB”) of 6 or more andtypically from about 8 to about 30. The HLB, as used herein, is thestandard HLB according to Griffin, J. Soc. Cosm. Chem., vol. 5, 249(1954). Preferably, the surfactant will be reasonably stable and foamthroughout a wide pH angle.

The oral compositions of the present invention comprise swellingsurfactant as part of gel network phase in an amount from about 0.01% toabout 15%, preferably from about 0.1% to about 10%, and more preferablyfrom about 0.3% to about 5%, by weight of the oral composition. In someembodiments, a diluted solution of surfactant in water is utilized. Inone embodiment, the amount of surfactant is chosen based on the level offoaming desired in the oral composition and on the irritation caused bythe surfactant. Once the level of surfactant is chosen, then the levelof fatty amphiphile that forms a gel network is chosen. For example, inoral compositions with high level of solvents, a greater amount of fattyamphiphile may be required whereas in oral compositions with low levelof solvents or water, a low level of fatty amphiphile may be chosen.

Suitable swelling surfactants include anionic, zwitterionic, amphoteric,cationic, and nonionic surfactants. In one embodiment, anionicsurfactants are preferred. The swelling surfactants may be a combinationof more than one type of surfactants, such as an anionic, nonionic, andzwitterionic surfactant.

Anionic surfactants useful herein include the water-soluble salts ofalkyl sulfate having from 8 to 20 carbon atoms in the alkyl radical(e.g., sodium alkyl sulfate) and the water-soluble salts of sulfonatedmonoglycerides of fatty acids having from 8 to 20 carbon atoms.Preferred anionic surfactants for use as swelling surfactants of thepresent invention include sodium lauryl sulfate, sodium laurylsarcosinate, sodium cocoyl methyl taurate, sodium monoglyceride sulfate,sodium cetaryl sulfate, potassium cocoyl glycinate, sodium laurylphosphate, sodium lauryl lactylate, sodium lauryl sulfoacetate, sodiumlauryl glutamate, sodium lauryl isethionate, sodium laureth carboxylate,sodium dodecyl benzenesulfonate, and combinations thereof. In oneembodiment, sodium lauryl sulfate is a preferred swelling surfactant.Many suitable anionic surfactants are disclosed by Agricola et al., U.S.Pat. No. 3,959,458, issued May 25, 1976.

Nonionic surfactants useful herein can be broadly defined as compoundsproduced by the condensation of alkylene oxide groups (hydrophilic innature) with an organic hydrophobic compound which may be aliphatic oralkyl-aromatic in nature. Nonlimiting examples of suitable nonionicsurfactants include polyoxyethylene sorbitan esters (sold under thetrade name Tweens), polyoxyl 40 hydrogenated castor oil, fatty alcoholethoxylates, ethylene oxide condensates of aliphatic alcohols, longchain tertiary amine oxides, long chain tertiary phosphaine oxides,lauryl glucoside (sold under the trade name Plantaren 1200 UP) and longchain dialkyl sulfoxides. Suitable nonionic surfactants with a HLB of 7or more include sucrose laurate, sucrose cocoate, sucrose stearate;Steareth 20, 21, or 100, and PEG 20 Sorbitan Monostearate (commerciallyavailable as Tween 60).

Amphoteric surfactants suitable as a swelling surfactant in the presentinvention can be broadly described as derivatives of aliphatic secondaryand tertiary amines in which the aliphatic radical can be a straightchain or branched and wherein one of the aliphatic substituents containsfrom about 8 to about 18 carbon atoms and one contains an anionicwater-solubilzing group, such as carboxylate, sulfonate, sulfate,phosphate, or phosphonate. Other suitable amphoteric surfactants arebetains, such as cocamidopropyl betaine, lauryl dimethyl betaine (soldunder the trade name Macat LB), cetyl dimethyl betaine, andcocoamphodiacetate. Additional amphoteric surfactants and nonionicsurfactants can be found in Gieske et al., U.S. Pat. No. 4,051,234,issued Sep. 27, 1977. Examples of suitable cationic surfactants includecetyl pyridinium chloride, coamidopropyl PG dimonium chloride phosphate(Phospholipid CDM), myristylamidopropyl PG dimonium chloride phosphate(Phospholipid PTM), stearamidopropyl PG dimonium chloride phosphate(Phospholipid SV), steapyrium chloride (Catemol WPC), and other suitablecationic materials.

More than one surfactant of the above specified types may be used forthe swelling surfactant of the present invention.

Another swelling surfactant or surfactant of any type may also be addedto the oral carrier phase of the oral composition. This surfactant maynot be part of the gel network as it does not participate in forming thegel network structure. The surfactant in the oral carrier phase mayprovide enhanced foaming or a different foaming profile. The surfactantadded to the oral carrier phase may also aid in modifying viscosity andchanging the flavor display.

B. Oral Carrier Materials

The oral compositions of the present invention comprise oral carriermaterials. The compositions comprise an oral carrier at a level of fromabout 5% to about 99%, preferably from about 10% to about 90%, by weightof the compositions. The oral carriers contained in this phase arebroadly described as any material in the oral composition that is notused to form the gel network. The oral carrier phase may be referred toas the bulk phase or solvent phase. The oral carriers are definedbroadly to include materials, such as abrasive or other non-solublematerials, that are solids (which may be described by certain analysisas not being in a particular phase). Oral carriers include cosmetic ortherapeutic actives and non-actives materials.

Oral carriers suitable for the preparation of oral composition are wellknown. Their selection will depend on secondary considerations liketaste, cost, stability, benefits desired, etc.

1. Cosmetic or Therapeutic Actives

The dentifrice composition may also comprise suitable cosmetic and/ortherapeutic actives. Such actives include any material that is generallyconsidered safe for use in the oral cavity and that provides changes tothe overall appearance and/or health of the oral cavity, including, butnot limited to, anti-calculus agents, fluoride ion sources, stannous ionsources, whitening agents, anti-microbial, anti-plaque agents,anti-inflammatory agents, nutrients, antioxidants, anti-viral agents,analgesic and anesthetic agents, H-2 antagonists, and mixture thereof.When present, the level of cosmetic and/or therapeutic active in theoral composition is, in one embodiment from about 0.001% to about 90%,in another embodiment from about 0.01% to about 50%, and in anotherembodiment from about 0.1% to about 30%, by weight of the oralcomposition.

The following is a non-limiting list of actives that may be used in thepresent invention.

a) Fluoride Ion

The present invention comprises a safe and effective amount of afluoride compound (e.g. water soluble). The fluoride ion is present inan amount sufficient to give a fluoride ion concentration in thecomposition at 25° C., and/or in one embodiment can be used at levels offrom about 0.0025% to about 5.0% by weight, in another embodiment fromabout 0.005% to about 2.0% by weight, to provide anticarieseffectiveness. A wide variety of fluoride ion-yielding materials can beemployed as sources of soluble fluoride in the present compositions.Examples of suitable fluoride ion-yielding materials are disclosed inU.S. Pat. Nos. 3,535,421, and 3,678,154. Representative fluoride ionsources include: stannous fluoride, sodium fluoride, potassium fluoride,amine fluoride, sodium monofluorophosphate and many others. In oneembodiment the dentifrice composition comprises stannous fluoride orsodium fluoride, as well as mixtures thereof.

b) Anticalculus Agent

Dentifrice compositions of the present invention may also comprise ananti-calculus agent, which in one embodiment may be present from about0.05% to about 50%, by weight of the dentifrice composition, in anotherembodiment is from about 0.05% to about 25%, and in another embodimentis from about 0.1% to about 15%. The anti-calculus agent may be selectedfrom the group consisting of polyphosphates (including pyrophosphates)and salts thereof; polyamino propane sulfonic acid (AMPS) and saltsthereof; polyolefin sulfonates and salts thereof; polyvinyl phosphatesand salts thereof; polyolefin phosphates and salts thereof;diphosphonates and salts thereof; phosphonoalkane carboxylic acid andsalts thereof; polyphosphonates and salts thereof; polyvinylphosphonates and salts thereof; polyolefin phosphonates and saltsthereof; polypeptides; and mixtures thereof. In one embodiment, thesalts are alkali metal salts. Polyphosphates are generally employed astheir wholly or partially neutralized water-soluble alkali metal saltssuch as potassium, sodium, ammonium salts, and mixtures thereof. Theinorganic polyphosphate salts include alkali metal (e.g. sodium)tripolyphosphate, tetrapolyphosphate, dialkyl metal (e.g. disodium)diacid, trialkyl metal (e.g. trisodium) monoacid, potassium hydrogenphosphate, sodium hydrogen phosphate, and alkali metal (e.g. sodium)hexametaphosphate, and mixtures thereof. Polyphosphates larger thantetrapolyphosphate usually occur as amorphous glassy materials. In oneembodiment the polyphosphates are those manufactured by FMC Corporation,which are commercially known as Sodaphos (n≈6), Hexaphos (n≈13), andGlass H (n≈21, sodium hexametaphosphate), and mixtures thereof. Thepyrophosphate salts useful in the present invention include, alkalimetal pyrophosphates, di-, tri-, and mono-potassium or sodiumpyrophosphates, dialkali metal pyrophosphate salts, tetraalkali metalpyrophosphate salts, and mixtures thereof. In one embodiment thepyrophosphate salt is selected from the group consisting of trisodiumpyrophosphate, disodium dihydrogen pyrophosphate (Na₂H₂P₂O₇),dipotassium pyrophosphate, tetrasodium pyrophosphate (Na₄P₂O₇),tetrapotassium pyrophosphate (K₄P₂O₇), and mixtures thereof. Polyolefinsulfonates include those wherein the olefin group contains 2 or morecarbon atoms, and salts thereof. Polyolefin phosphonates include thosewherein the olefin group contains 2 or more carbon atoms.Polyvinylphosphonates include polyvinylphosphonic acid. Diphosphonatesand salts thereof include azocycloalkane-2,2-diphosphonic acids andsalts thereof, ions of azocycloalkane-2,2-diphosphonic acids and saltsthereof, azacyclohexane-2,2-diphosphonic acid,azacyclopentane-2,2-diphosphonic acid,N-methyl-azacyclopentane-2,3-diphosphonic acid, EHDP(ethane-1-hydroxy-1,1,-diphosphonic acid), AHP(azacycloheptane-2,2-diphosphonic acid),ethane-1-amino-1,1-diphosphonate, dichloromethane-diphosphonate, etc.Phosphonoalkane carboxylic acid or their alkali metal salts include PPTA(phosphonopropane tricarboxylic acid), PBTA(phosphonobutane-1,2,4-tricarboxylic acid), each as acid or alkali metalsalts. Polyolefin phosphates include those wherein the olefin groupcontains 2 or more carbon atoms. Polypeptides include polyaspartic andpolyglutamic acids.

c) Stannous Ion

The dentifrice compositions of the present invention may include astannous ion source. The stannous ions may be provided from stannousfluoride and/or other stannous salts. Stannous fluoride has been foundto help in the reduction of gingivitis, plaque, sensitivity, and inimproved breath benefits. The stannous ions provided in a dentifricecomposition will provide efficacy to a subject using the dentifricecomposition. Although efficacy could include benefits other than thereduction in gingivitis, efficacy is defined as a noticeable amount ofreduction in in situ plaque metabolism. Formulations providing suchefficacy typically include stannous levels provided by stannous fluorideand/or other stannous salts ranging from about 3,000 ppm to about 15,000ppm stannous ions in the total dentifrice composition. The stannous ionis present in an amount of from about 4,000 ppm to about 12,000 ppm, inone embodiment from about 5,000 ppm to about 10,000 ppm. Other stannoussalts include organic stannous carboxylates, such as stannous acetate,stannous gluconate, stannous oxalate, stannous malonate, stannouscitrate, stannous ethylene glycoxide, stannous formate, stannoussulfate, stannous lactate, stannous tartrate, and the like. Otherstannous ion sources include, stannous halides such as stannouschlorides, stannous bromide, stannous iodide and stannous chloridedihydride. In one embodiment the stannous ion source is stannousfluoride in another embodiment, stannous chloride dihydrate. Thecombined stannous salts may be present in an amount of from about 0.001%to about 11%, by weight of the dentifrice compositions. The stannoussalts may, in one embodiment, be present in an amount of from about0.01% to about 7%, in another embodiment from about 0.1% to about 5%,and in another embodiment from about 1.5% to about 3%, by weight of thedentifrice composition.

d) Whitening Agent

A whitening agent may be included as an active in the present dentifricecompositions. The actives suitable for whitening are selected from thegroup consisting of alkali metal and alkaline earth metal peroxides,metal chlorites, perborates inclusive of mono and tetrahydrates,perphoshates, percarbonates, peroxyacids, and persulfates, such asammonium, potassium, sodium and lithium persulfates, and combinationsthereof. Suitable peroxide compounds include hydrogen peroxide, ureaperoxide, calcium peroxide, carbamide peroxide, magnesium peroxide, zincperoxide, strontium peroxide and mixtures thereof. In one embodiment theperoxide compound is carbamide peroxide. Suitable metal chloritesinclude calcium chlorite, barium chlorite, magnesium chlorite, lithiumchlorite, sodium chlorite, and potassium chlorite. Additional whiteningactives may be hypochlorite and chlorine dioxide. In one embodiment thechlorite is sodium chlorite. In another embodiment the percarbonate issodium percarbonate. In one embodiment the persulfates are oxones. Thelevel of these substances is dependent on the available oxygen orchlorine, respectively, that the molecule is capable of providing tobleach the stain. In one embodiment the whitening agents may be presentat levels from about 0.01% to about 40%, in another embodiment fromabout 0.1% to about 20%, in another embodiment form about 0.5% to about10%, and in another embodiment from about 4% to about 7%, by weight ofthe dentifrice composition. The gel network composition may contain awhitening agent or peroxide or it may be contained in the oral carrierphase. The gel network may aid in the stabilizing of peroxides.

e) Anti-Microbial Agent

Anti-microbial agents may be included in the dentifrice compositions ofthe present invention. Such agents may include, but are not limited to:5-chloro-2-(2,4-dichlorophenoxy)-phenol, commonly referred to astriclosan; 8-hydroxyquinoline and its salts; copper II compounds,including, but not limited to, copper(II) chloride, copper(II) sulfate,copper(II) acetate, copper(II) fluoride and copper(II) hydroxide;phthalic acid and its salts including, but not limited to thosedisclosed in U.S. Pat. No. 4,994,262, including magnesium monopotassiumphthalate; chlorhexidine; alexidine; hexetidine; sanguinarine;benzalkonium chloride; salicylanilide; domiphen bromide; cetylpyridiniumchloride (CPC); tetradecylpyridinium chloride (TPC);N-tetradecyl-4-ethylpyridinium chloride (TDEPC); octenidine; iodine;sulfonamides; bisbiguanides; phenolics; delmopinol, octapinol, and otherpiperidino derivatives; niacin preparations; zinc or stannous ionagents; nystatin; grapefruit extract; apple extract; thyme oil; thymol;antibiotics such as augmentin, amoxicillin, tetracycline, doxycycline,minocycline, metronidazole, neomycin, kanamycin, cetylpyridiniumchloride, and clindamycin; analogs and salts of the above; methylsalicylate; hydrogen peroxide; metal salts of chlorite; and mixtures ofall of the above. Soluble or insoluble zinc salts, such as zinc citrate,zinc oxide, zinc lactate, and other zinc species may be used as ananti-microbial or anti-plaque agent or for various other benefits.Anti-microbial components may be present from about 0.001% to about 20%by weight of the dentifrice composition. In another embodiment theantimicrobial agents generally comprise from about 0.1% to about 5% byweight of the dentifrice compositions of the present invention.

f) Anti-Plaque Agent

The dentifrice compositions of the present invention may include ananti-plaque agent such as stannous salts, copper salts, strontium salts,magnesium salts or a dimethicone copolyol. The dimethicone copolyol isselected from C12 to C20 alkyl dimethicone copolyols and mixturesthereof. In one embodiment the dimethicone copolyol is cetyl dimethiconecopolyol marketed under the Trade Name Abil EM90. The dimethiconecopolyol in one embodiment can be present in a level of from about0.001% to about 25%, in another embodiment from about 0.01% to about 5%,and in another embodiment from about 0.1% to about 1.5% by weight of thedentifrice composition.

g) Anti-Inflammatory Agent

Anti-inflammatory agents can also be present in the dentifricecompositions of the present invention. Such agents may include, but arenot limited to, non-steroidal anti-inflammatory (NSAID) agents oxicams,salicylates, propionic acids, acetic acids and fenamates. Such NSAIDsinclude but are not limited to ketorolac, flurbiprofen, ibuprofen,naproxen, indomethacin, diclofenac, etodolac, indomethacin, sulindac,tolmetin, ketoprofen, fenoprofen, piroxicam, nabumetone, aspirin,diflunisal, meclofenamate, mefenamic acid, oxyphenbutazone,phenylbutazone and acetaminophen. Use of NSAIDs such as ketorolac areclaimed in U.S. Pat. No. 5,626,838. Disclosed therein are methods ofpreventing and/or treating primary and reoccurring squamous cellcarcinoma of the oral cavity or oropharynx by topical administration tothe oral cavity or oropharynx of an effective amount of an NSAID.Suitable steroidal anti-inflammatory agents include corticosteroids,such as fluccinolone, and hydrocortisone.

h) Nutrients

Nutrients may improve the condition of the oral cavity and can beincluded in the dentifrice compositions of the present invention.Nutrients include minerals, vitamins, oral nutritional supplements,enteral nutritional supplements, and mixtures thereof. Useful mineralsinclude calcium, phosphorus, zinc, manganese, potassium and mixturesthereof. Vitamins can be included with minerals or used independently.Suitable vitamins include Vitamins C and D, thiamine, riboflavin,calcium pantothenate, niacin, folic acid, nicotinamide, pyridoxine,cyanocobalamin, para-aminobenzoic acid, bioflavonoids, and mixturesthereof. Oral nutritional supplements include amino acids, lipotropics,fish oil, and mixtures thereof. Amino acids include, but are not limitedto L-Tryptophan, L-Lysine, Methionine, Threonine, Levocarnitine orL-carnitine and mixtures thereof. Lipotropics include, but are notlimited to, choline, inositol, betaine, linoleic acid, linolenic acid,and mixtures thereof. Fish oil contains large amounts of Omega-3 (N-3)polyunsaturated fatty acids, eicosapentaenoic acid and docosahexaenoicacid. Enteral nutritional supplements include, but are not limited to,protein products, glucose polymers, corn oil, safflower oil, mediumchain triglycerides. Minerals, vitamins, oral nutritional supplementsand enteral nutritional supplements are described in more detail in DrugFacts and Comparisons (loose leaf drug information service), WoltersKluer Company, St. Louis, Mo., © 1997, pps. 3-17 and 54-57.

i) Antioxidants

Antioxidants are generally recognized as useful in dentifricecompositions. Antioxidants are disclosed in texts such as Cadenas andPacker, The Handbook of Antioxidants, © 1996 by Marcel Dekker, Inc.Antioxidants useful in the present invention include, but are notlimited to, Vitamin E, ascorbic acid, Uric acid, carotenoids, Vitamin A,flavonoids and polyphenols, herbal antioxidants, melatonin,aminoindoles, lipoic acids and mixtures thereof.

j) Analgesic and Anesthetic Agents

Anti-pain or desensitizing agents can also be present in the dentifricecompositions of the present invention. Analgesics are agents thatrelieve pain by acting centrally to elevate pain threshold withoutdisturbing consciousness or altering other sensory modalities. Suchagents may include, but are not limited to: strontium chloride;potassium nitrate; sodium fluoride; sodium nitrate; acetanilide;phenacetin; acertophan; thiorphan; spiradoline; aspirin; codeine;thebaine; levorphenol; hydromorphone; oxymorphone; phenazocine;fentanyl; buprenorphine; butaphanol; nalbuphine; pentazocine; naturalherbs, such as gall nut; Asarum; Cubebin; Galanga; scutellaria;Liangmianzhen; and Baizhi. Anesthetic agents, or topical analgesics,such as acetaminophen, sodium salicylate, trolamine salicylate,lidocaine and benzocaine may also be present. These analgesic activesare described in detail in Kirk-Othmer, Encyclopedia of ChemicalTechnology, Fourth Edition, Volume 2, Wiley-Interscience Publishers(1992), pp. 729-737.

k) H-1 and H-2 Antagonists

The present invention may also optionally comprise selective H-1 and H-2antagonists including compounds disclosed in U.S. Pat. No. 5,294,433.

l) Antiviral Actives

Antiviral actives useful in the present composition include any knowactives that are routinely use to treat viral infections. Suchanti-viral actives are disclosed in Drug Facts and Comparisons, WoltersKluer Company, ©1997, pp. 402(a)-407(z). Specific examples includeanti-viral actives disclosed in U.S. Pat. No. 5,747,070, issued May 5,1998. Said Patent discloses the use of stannous salts to controlviruses. Stannous salts and other anti-viral actives are described indetail in Kirk & Othmer, Encyclopedia of Chemical Technology, ThirdEdition, Volume 23, Wiley-Interscience Publishers (1982), pp. 42-71. Thestannous salts that may be used in the present invention would includeorganic stannous carboxylates and inorganic stannous halides. Whilestannous fluoride may be used, it is typically used only in combinationwith another stannous halide or one or more stannous carboxylates oranother therapeutic agent.

m) Chelant

Chelating agents are able to complex calcium found in the cell walls ofbacteria and can help to disrupt plaque by removing calcium from thecalcium bridges which help hold this biomass intact. Suitable chelatingagents include tartaric acid and salts thereof, citric acid and alkalimetal citrates, soluble pyrophosphates, anionic polymericpolycarboxylates, and combinations thereof.

n) Anti-Erosion Agents

The present compositions optionally contain anti-erosion agents such asdescribed in commonly-assigned U.S. Pat. No. 6,685,920. Dental erosionis a permanent loss of tooth substance from the surface by the action ofchemicals, such as harsh abrasives and acids, as opposed to subsurfacedemineralization or caries caused by bacterial action. Anti-erosionagents described therein have affinity for the tooth surface. Theseagents either bind to the tooth surface or form insoluble compounds orcomplexes on the tooth surface, thereby forming a protective film orcoating on the tooth surface. As a result of these protective coatings,teeth are provided with remarkable resistance and protection againstdental erosion challenges for extended periods of time following use ofthe composition containing these agents. Useful anti-erosion agentsinclude polymeric mineral surface active agents such as condensedphosphorylated polymers; polyphosphonates; polycarboxylates andcarboxy-substituted polymers; copolymers of phosphate- orphosphonate-containing monomers or polymers with ethylenicallyunsaturated monomers, amino acids, or with other polymers selected fromproteins, polypeptides, polysaccharides, poly(acrylate),poly(acrylamide), poly(methacrylate), poly(ethacrylate),poly(hydroxyalkylmethacrylate), poly(vinyl alcohol), poly(maleicanhydride), poly(maleate) poly(amide), poly(ethylene amine),poly(ethylene glycol), poly(propylene glycol), poly(vinyl acetate) orpoly(vinyl benzyl chloride); and mixtures thereof. Also useful asanti-erosion agents are metal ions selected from stannous, zinc andcopper, which deposit onto teeth a highly insoluble film or precipitateof compounds or complexes formed from the reaction of the metal ionswith other ingredients of the oral composition and/or components of theenamel surface.

o) Additional Actives

Additional actives suitable for use in the present invention mayinclude, but are not limited to, insulin, steroids, natural materials,herbal and other plant derived remedies. Additionally, anti-gingivitisor gum care agents known in the art may also be included. Componentswhich impart a clean feel to the teeth may optionally be included. Thesecomponents may include, for example, baking soda or Glass-H. Also, it isrecognized that in certain forms of therapy, combinations of theseabove-named agents may be useful in order to obtain an optimal effect.Thus, for example, an anti-microbial and an anti-inflammatory agent maybe combined in a single dentifrice composition to provide combinedeffectiveness. Other ingredients, such as materials providinganti-sensitivity benefits, may also be used.

Optional agents to be used include such known materials as syntheticanionic polymers, including polyacrylates and copolymers of maleicanhydride or acid and methyl vinyl ether (e.g., Gantrez), as described,for example, in U.S. Pat. No. 4,627,977, as well as, e.g., polyaminopropoane sulfonic acid (AMPS), zinc citrate trihydrate, polyphosphates(e.g., tripolyphosphate; hexametaphosphate), diphosphonates (e.g., EHDP;AHP), polypeptides (such as polyaspartic and polyglutamic acids), andmixtures thereof. Additionally, the dentifrice composition can include apolymer carrier, such as those described in U.S. Pat. Nos. 6,682,722 and6,589,512 and U.S. application Ser. Nos. 10/424,640 and 10/430,617.

2. Additional Oral Carriers a) Buffering Agents

The oral compositions may contain a buffering agent. Buffering agents,as used herein, refer to agents that can be used to adjust the pH of theoral compositions to a range of about pH 3.0 to about pH 10. Thebuffering agents include alkali metal hydroxides, ammonium hydroxide,organic ammonium compounds, carbonates, sesquicarbonates, borates,silicates, phosphates, imidazole, and mixtures thereof. Specificbuffering agents include monosodium phosphate, trisodium phosphate,sodium benzoate, benzoic acid, sodium hydroxide, potassium hydroxide,alkali metal carbonate salts, sodium carbonate, imidazole, pyrophosphatesalts, citric acid, and sodium citrate. Buffering agents are used at alevel of from about 0.1% to about 30%, preferably from about 0.1% toabout 10%, and more preferably from about 0.3% to about 3%, by weight ofthe oral composition.

b) Abrasive Polishing Materials

An abrasive polishing material may also be included in the oralcompositions. The abrasive polishing material contemplated for use inthe compositions of the present invention can be any material that doesnot excessively abrade dentin. Typical abrasive polishing materialsinclude silicas including gels and precipitates; aluminas; phosphatesincluding orthophosphates, polymetaphosphates, and pyrophosphates; andmixtures thereof. Specific examples include dicalcium orthophosphatedihydrate, calcium pyrophosphate, tricalcium phosphate, calciumpolymetaphosphate, insoluble sodium polymetaphosphate, rice hull silica,hydrated alumina, beta calcium pyrophosphate, calcium carbonate, andresinous abrasive materials such as particulate condensation products ofurea and formaldehyde, and others such as disclosed by Cooley et al inU.S. Pat. No. 3,070,510, issued Dec. 25, 1962. Mixtures of abrasives mayalso be used. If the oral composition or particular phase comprises apolyphosphate having an average chain length of about 4 or more, calciumcontaining abrasives and alumina are not preferred abrasives. The mostpreferred abrasive is silica.

Silica dental abrasives of various types are preferred because of theirunique benefits of exceptional dental cleaning and polishing performancewithout unduly abrading tooth enamel or dentine. The silica abrasivepolishing materials herein, as well as other abrasives, generally havean average particle size ranging between about 0.1 to about 30 microns,and preferably from about 5 to about 15 microns. The abrasive can beprecipitated silica or silica gels such as the silica xerogels describedin Pader et al., U.S. Pat. No. 3,538,230, issued Mar. 2, 1970, andDiGiulio, U.S. Pat. No. 3,862,307, issued Jan. 21, 1975. Preferred arethe silica xerogels marketed under the trade name “Syloid” by the W.R.Grace & Company, Davison Chemical Division. Also preferred are theprecipitated silica materials such as those marketed by the J. M. HuberCorporation under the trade name, “Zeodent”, particularly the silicacarrying the designation “Zeodent 119.” The types of silica dentalabrasives useful in the toothpastes of the present invention aredescribed in more detail in Wason, U.S. Pat. No. 4,340,583, issued Jul.29, 1982. Silica abrasives are also described in Rice, U.S. Pat. Nos.5,589,160; 5,603,920; 5,651,958; 5,658,553; and 5,716,601. The abrasivein the oral compositions described herein is generally present at alevel of from about 6% to about 70% by weight of the composition.Preferably, oral compositions contain from about 10% to about 50% ofabrasive, by weight of the oral composition.

c) Titanium Dioxide

Titanium dioxide may also be added to the present composition. Titaniumdioxide is a white powder which adds opacity to the compositions.Titanium dioxide generally comprises from about 0.25% to about 5%, byweight of the composition.

d) Coloring Agents

Coloring agents may also be added to the present composition. Thecoloring agent may be in the form of an aqueous solution, preferably 1%coloring agent in a solution of water. Pigments, pealing agents, fillerpowders, talc, mica, magnesium carbonate, calcium carbonate, bismuthoxychloride, zinc oxide, and other materials capable of creating avisual change to the oral compositions may also be used. Color solutionsand other agents generally comprise from about 0.01% to about 5%, byweight of the composition.

e) Flavoring Components

Suitable flavoring components include oil of wintergreen, clove bud oil,menthol, anethole, methyl salicylate, eucalyptol, cassia, 1-menthylacetate, sage, eugenol, parsley oil, oxanone, alpha-irisone, marjoram,lemon, orange, propenyl guaethol, cinnamon, vanillin, ethyl vanillin,heliotropine, 4-cis-heptenal, diacetyl, methyl-para-tert-butyl phenylacetate, cranberry, chocolate, green tea, and mixtures thereof. Coolantsmay also be part of the flavor composition. Coolants suitable for thepresent compositions include the paramenthan carboxyamide agents such asN-ethyl-p-menthan-3-carboxamide (known commercially as WS-3, WS-23,WS-5), MGA, TK-10, Physcool, and mixtures thereof. Salivating agents,warming agents, numbing agents, and other optional materials can be usedto deliver a signal while the oral composition is being used. A flavorcomposition is generally used in the oral care compositions at levels offrom about 0.001% to about 5%, by weight of the oral care composition.The flavor composition will preferably be present in an amount of fromabout 0.01% to about 4%, more preferably from about 0.1% to about 3%,and more preferably from about 0.5% to about 2% by weight.

f) Sweetening Agents

Sweetening agents can be added to the compositions. These includesaccharin, dextrose, sucrose, lactose, xylitol, maltose, levulose,aspartame, sodium cyclamate, D-tryptophan, dihydrochalcones, acesulfame,sucralose, neotame, and mixtures thereof. Various coloring agents mayalso be incorporated in the present invention. Sweetening agents aregenerally used in toothpastes at levels of from about 0.005% to about5%, by weight of the composition.

g) Thickening Agents

Although the oral composition of the present invention is structured orthickened by the gel network, additional thickening agents, such aspolymeric thickeners, may be utilized. In some embodiments, the majorityof the structuring of the oral composition is from the gel network. Inother embodiments, the majority of the structuring may be from apolymeric thickening agent with the gel network providing additionalstructuring to the oral composition.

Suitable thickening agents are carboxyvinyl polymers, carrageenan,hydroxyethyl cellulose, laponite and water soluble salts of celluloseethers such as sodium carboxymethylcellulose and sodium carboxymethylhydroxyethyl cellulose. Natural gums such as gum karaya, xanthan gum,gum arabic, and gum tragacanth can also be used. Colloidal magnesiumaluminum silicate or finely divided silica can be used as part of thethickening agent to further improve texture. Several suitable thickeningsilicas are known and used in oral compositions. Thickening agents caninclude polymeric polyether compounds, e.g., polyethylene orpolypropylene oxide (M.W. 300 to 1,000,000), capped with alkyl or acylgroups containing 1 to about 18 carbon atoms.

A suitable class of thickening or gelling agents includes a class ofhomopolymers of acrylic acid crosslinked with an alkyl ether ofpentaerythritol or an alkyl ether of sucrose, or carbomers. Carbomersare commercially available from B.F. Goodrich as the Carbopol® series.Particularly the carbopols include Carbopol 934, 940, 941, 956, andmixtures thereof.

Copolymers of lactide and glycolide monomers, the copolymer having themolecular weight in the range of from about 1,000 to about 120,000(number average), are useful for delivery of actives into theperiodontal pockets or around the periodontal pockets as a “subgingivalgel carrier.” These polymers are described in U.S. Pat. Nos. 5,198,220;5,242,910; and 4,443,430.

Thickening agents in an amount from about 0% to about 15%, or from about0.01% to about 6%, in another embodiment from about 0.1% to about 5%, byweight of the total oral composition, can be used. The oral compositioncan be essentially free of thickening agents if it is structured orthickened by the gel network. In other embodiments, a small amount of athickening agent, such as from about 0.01% to about 1% or from about0.05% to about 0.5%, can be used in combination with the gel network.The specific amount of thickening agent will be selected based on thedesired rheology and function of the gel network.

h) Humectant

A humectant can help to keep the dentifrice composition from hardeningupon exposure to air and provide a moist feel in the mouth. A solvent isrequired in the gel network. A humectant or additional solvent may beadded to the oral carrier phase. Suitable humectants for the presentinvention include water, edible polyhydric alcohols such as glycerin,sorbitol, xylitol, butylene glycol, polyethylene glycol, propyleneglycol, and combinations thereof. Sorbitol, glycerin, water, andcombinations thereof are preferred humectants. The humectant may bepresent in an amount of from about 0% to about 99%, from about 0.5% toabout 95%, and from about 1% to about 90%. The oral carrier phase canalso be made without a humectant. The oral composition structured with agel network instead of typical polyermic thickener, or with low levelsof polymeric thickeners, may not require a humectant or may allow forlower levels of humectants. The oral composition with the gel networkwill typically provide a moist mouthfeel and/or not become dried outwhen exposed to air. A gel network composition could be free ofhumectants or anhydrous for use as a denture adhesive composition.

i) Sufactants

An additional surfactant other than the dispersing surfactant and theswelling surfactant may be added to the oral carrier phase of the oralcomposition. This may be the same surfactant that is added to the gelnetwork phase or a different surfactant. A surfactant may aid in thecleaning or foaming of the oral composition. Suitable surfactants aredescribed previously.

C. Process of Making an Oral Composition

An aspect of the invention relates to a process of making an oralcomposition of the present invention. The process of making an oralcomposition comprises forming a gel network from a fatty amphiphiledispersion. The advantages of this method of forming a gel network froma pre-made fatty amphiphile dispersion that has controlled or limitedswelling over the typical process of forming a gel network are many. Itenables the pre-mix of the fatty amphiphile material to be formed priorto processing giving additional flexibility and reduction in makingtimes. The fatty amphiphile contained is the fatty amphiphile dispersionis the only part of the oral composition that needs to be heated as theswelling surfactant can be added to the fatty amphiphile dispersion atany temperature due to the dispersing surfactant. This reduces the totalenergy needed to make the oral composition as a very small amount ofmaterials need to be heated. Additionally, materials that are notheat-stable or can be negatively affected by heat can be added to theformulation.

The fatty amphiphile dispersion is formed by heating the fattyamphiphile, and optionally the dispersing surfactant and solvent, to atemperature sufficient to allow emulsification of the fatty amphiphile,typically at least about 5° C. above the melt temperature of the fattyamphiphile. The fatty amphiphile dispersion may cool below the melttemperature of the fatty amphiphile. Oral carrier ingredients mayoptionally be added at any time to the fatty amphiphile dispersionduring the process such as before heating, during heating, beforecooling, or after cooling. It may be desired to add suppressingmaterials to this dispersion.

In one embodiment of the present invention, the fatty amphiphiledispersion of the present invention may be prepared by heating the fattyamphiphile to a level of at least 5° C. above the melt temperature ofthe fatty amphiphile. If more than one fatty amphiphile is used, thedispersion should be heated at least 5° C. above the melt temperature ofthe fatty amphiphile with the highest melt temperature. Preferably, thefatty amphiphile is heated 10° C. above the highest fatty amphiphilemelt temperature. The heating may be in the range of about 50° C. toabout 90° C., typically from about 70° C. to about 90° C. The dispersingsurfactant and solvent can be added to the fatty amphiphile while it ishot enabling the fatty amphiphile dispersion to form. The materials canbe mixed during heating, after heating, during cooling, and aftercooling. Mixing or providing shear reduces the particle size of themelted fatty amphiphile. In one embodiment, the fatty amphiphile isheated and then homogenized for 1 minute. After being heated, themixture may cool to a level in the range of about 20° C. to about 35° C.Depending upon the size of the batch, equipment, specific materials, andtime, the fatty amphiphile dispersion may be cooled by mixing only, anice bath, or passing the mixture through a heat exchanger. Coolingquickly, such as around or more than 1 degree per minute, can help toset particle size and/or make the particle size more consistent. In analternative method, the fatty amphiphile dispersion is heated and formedand while still at a high temperature, the swelling surfactant andsolvent can be added. It may be desired in some processes to add thefatty amphiphile dispersion while it is warm and while it is easy topump. If desired, the fatty amphiphile dispersion can be made severalhours or days ahead of time and stored prior to making the final oralcomposition.

In one embodiment, the fatty amphiphile dispersion is added to theremaining oral carrier materials, including additional solvents, andthen finally the swelling surfactant is added to form the gel network.The fatty amphiphile and the swelling surfactant interact to form acrystalline gel network. The additional oral carrier materials can beadded during the formation of the fatty amphiphile dispersion, after thedispersion is formed, with the swelling surfactant, and/or after theswelling surfactant has been added. It is typically desired that theswelling surfactant is not added to the fatty amphiphile dispersionfirst as it gets too viscous and hard to process. Preferably, theswelling surfactant is not added to the fatty amphiphile dispersionbefore the dispersion is mixed with additional oral carrier materialsand the fatty amphiphile dispersion is free of swelling surfactant. Aswelling surfactant and solvent premix can be added to the fattyamphiphile dispersion or the solvent and other oral care materials addedfirst.

Sonication and/or milling of the fatty amphiphile, the dispersingsurfactant, and solvent, before, while, or after these components areheated will aid in further reduction of the particle size of the meltedfatty amphiphile phase. This results in an increase in surface area ofthe fatty amphiphile phase and a reduced viscosity. The increase insurface area of the fatty amphiphile dispersion also allows the swellingsurfactant and the solvent to interact with the fatty amphiphiledispersion. Another suitable variation in preparing the gel networkincludes heating and mixing the fatty amphiphile and the dispersingsurfactant first, and then adding that mixture to the solvent to formthe fatty amphiphile dispersion.

The gel network can be used by itself to structure or thicken the oralcomposition to provide the desired rheology. The gel network can also beused in combination with other thickening materials. Other polymericthickening materials may be desired to aid in rheology temperaturestability of the oral composition. The polymeric thickeners may or maynot contribute to the rheology at room temperature. The gel network maybe formulated to produce a dentifrice: having rheology enabling thesolids and other particles to be suspended, easily dispensed from acontainer, stand-up on a toothbrush head once the dentifrice isdispensed, low or no stringiness when dispensed, ease of dispersal inthe mouth, and other rheological properties desired of a dentifrice.

The viscosity of the dentifrice is typically from about 5 to about 100BKU, from about 8 to about 50 BKU, and commonly from about 10 to about50 BKU as measured at the time the dentifrice is packed. The viscosityof the dentifrice may increase to as great at 200 BKU after packing andbefore use, particularly if polymeric thickeners are included in thedentifrice. As used herein, BKU is the unit of viscosity. The viscometeris Brookfield viscometer, Model ½ RVT (½ spring strength), with aBrookfield “Heliopath” stand. The spindle is a conventional “E-series”T-shaped spindle. The viscometer is placed on the Heliopath stand andleveled via spirit levels. The E spindle is attached, and the viscometeris set to 2.5 RPM while it is running The viscosity is measured after 1minute and the temperature is constant at 25° C. The dentifricecomposition will have an acceptable rheology, good texture, pleasingaesthetics, and a de-aerated specific gravity from about 0.9 to about1.8 and can be from about 1.1 to about 1.6.

D. Method of Use

The compositions of the present invention are used in a conventionalmanner for cleansing the teeth. Generally, a method of using adentifrice to cleanse the teeth comprises applying the composition ofthe present invention to a toothbrush, brushing the teeth for a periodof time, and then rinsing the dentifrice from the mouth. From about 0.01to about 3 grams of toothpaste is typically used.

Non-Limiting Examples

The oral compositions illustrated in the following Examples illustratespecific embodiments of the oral compositions of the present invention,but are not intended to be limiting thereof. Other modifications can beundertaken by the skilled artisan without departing from the spirit andscope of this invention.

Although oral compositions are the focus of this application, thetwo-step method of producing gel networks by first forming a fattyamphiphile dispersion could be used in other product areas. Suitableproduct areas would include any product that contains a gel network.Examples are shampoos, conditioners, hair colorants, fabric enhancers,fabric softeners, liquid detergents, liquid dish soaps for hand dishwashing or dishwashers, personal care compositions for cleansing ormoisturizing, skin care, body washes, and other similar products.

Oral Composition Examples

The following Examples illustrate specific embodiments of the oralcomposition utilizing gel networks.

In examples 1-5, a fatty amphiphile dispersion is formed in Step 1. TheStep 1 materials are combined in a mixing vessel, mixed, and heated tobetween about 75° C. to about 80° C. It may be desired to only heat thefatty amphiphile and then add the remaining Step 1 materials. Thematerials are mixed for 1 minute at 750 watt vibra cell ultrasonichomogenizer from Sonics and Materials, Inc. The fatty amphiphiledispersion is rapidly cooled with mixing to about 25-30° C. The fattyamphiphile dispersion is then added to the materials in Step 2. A gelnetwork is formed once the swelling surfactant is added. The flavor maybe added in Step 1 as a suppressing material, may be added in Step 2, ormay be added as the final ingredient to minimize volatile loss.

EXAMPLES 1-4

Step 1: Fatty Amphiphile Dispersion materials are listed in weightpercent of the fatty amphiphile dispersion.

Example Example Example Example Example Ingredients 1 2 3 4 5 CetylAlcohol 20 20 20 0 20 Stearyl Alcohol 20 20 20 35 20 Glycerylmonostearate 0 0 0 5 0 (40% mono) Water 58.5 59.5 59.5 64.5 0 Glycerin 00 0 0 59.5 Ganex P904 1.5 0 0 0 0 Inutec SP1 0 0.5 0 0 0 Natrusol Plus 00 0.5 0.5 0.5Step 2: Oral composition materials are listed in weight percent of thefinal composition.

Example Example Example Example Example Ingredients 1 2 3 4 5 FattyAmphiphile  9.5%  7.5%   15%   11% 3.75%  Dispersion from above Glycerin(@99.7%) 38.00%  64.95%    44% 35.546%   Sorbitol (@70%) 0 0 20.0% 0 0Glass H polyphosphate 0 0 0 0  13% Sodium Lauryl Sulfate 3.00% 3.50%5.00% 7.00% 2.5% (@28%) Water 25.45 0 16.7 25.28 0 Sodium Fluoride 0.24%0.24% 0 0.24% 0 Stannous Fluoride 0 0 0 0 0.454%  Zinc Lactate Dyhydrate0 0 0 0 2.5% Sodium Gluconate 0 0 0 0 0.65%  PEG-300 0 0 0 0   7%Propylene Glycol 0 0 0 0   7% Disodium MonoFluoro 0 0 0.80% 0 0Phosphate (MFP) Calcium Carbonate (ground limestone 0 0 40.00%  0 02531) Silica 17.00%  17.00%  0 5.00%  25% Sodium Acid 1.00% 1.00% 0 0 0Pyrophosphate Tetra Sodium 3.85% 3.85% 1.00% 6.00% 0 PyrophosphateSodium Saccharin 0.46% 0.46% 0.50% 0.48% 0.5% Titanium Dioxide 0.50%0.50% 0 0 0 Trisodium Phosphate 0 0 0 0 1.1% Peppermint Flavor 1.00%1.00% 1.00% 1.00% 1.00% 

The viscosity of the fatty amphiphile dispersion was measured 24 hoursafter it was made and stored at room temperature. The viscosity of thefatty amphiphile dispersion when placed in water with 15% fattyamphiphile dispersion and 5% sodium lauryl sulfate solution was alsomeasured at 24 hours. As used herein, cps is the unit of viscosity. Theviscometer is Brookfield viscometer, Model ½ RVT (½ spring strength),with a Brookfield “Heliopath” stand. The spindle is a conventional“E-series” T-shaped spindle. The viscometer is placed on the Heliopathstand and leveled via spirit levels. The E spindle is attached, and theviscometer is set to 2.5 RPM while it is running. The viscosity ismeasured after 30 seconds and the temperature is constant at 25° C.

Viscosity Example 1 Example 2 Example 3 Fatty amphiphile 370,000 cps50,000 cps 50,000 cps dispersion

In other examples, a concentrated dentifrice may be formed. Theconcentrated dentifrice is structured by a gel network. After packaging,a solvent, preferably water, could be added to the concentrateddentifrice to form dentifrice with typical levels of actives andrheology for brushing. In certain formulations, an oral care compositionstructured by a gel network retains a homogeneous structure when dilutedwith excess amounts of water or other solvents. This is in contrast totypical polymer thickened oral compositions. The concentrated dentifricemay be formulated to contain twice, three times, four times, five times,or more of the amount of active or solid materials as in typicaldentifrice compositions. The concentrated dentifrice can be dilutedprior to use or during use.

More than one gel network composition may be used in an oralcomposition. Two or more gel network compositions can be used tostructure the oral composition. Alternatively, one gel networkcomposition can be used to structure the oral composition and a secondgel network to aid in the delivery of a material, such as a flavor. Twoor more gel network compositions may also be desired to achieve certainvisual appearances such as striped or multicolor products. It may bedesired to have more than one gel network composition in an oral carecomposition to provide color stability, flavor delivery, or incorporateincompatible materials. The gel network composition may also aid insequestering flavors or coolants or other large organic materials forvarious types of flavor displays. The gel network composition may alsoaid in the delivery of cationic, anionic, hydrophilic, hydrophobic,insoluble, or soluble materials or combinations thereof. This may bebeneficial in delivering incompatible materials. The gel networkcomposition may also aid in targeting the delivery, release, or extendeddelivery of materials such as actives, flavors, or other materials foraesthetic reasons or other benefits.

Analytical Methods and Examples

The following methods are used to identify gel networks.

Differential Scanning Calorimetry Method

The chain melt temperature of the layer in the gel network comprisingthe one or more fatty amphiphiles (i.e., the melt transition temperaturefor the gel network) may be obtained using differential scanningcalorimetry according to the following method. Utilizing a TAInstruments Q100 DSC, approximately 50 mg of the gel network pre-mix orthe final oral composition containing the gel network is placed into astainless steel high volume DSC pan. The sample, along with an emptyreference pan is placed into the instrument. The samples are analyzedusing the following conditions/temperature program: Nitrogen Purge,Equilibrate @ 5.00° C. until an isothermal is reach for 2.00 min. Rampthe temperature at a rate of 3.00° C./min to 90.00 ° C. Each sample isanalyzed in duplicate. The resulting DSC data is analyzed using TAInstruments Universal Analysis Software.

The use of DSC to measure the melt transition temperature for gelnetworks is further described by T. de Vringer et al., Colloid andPolymer Science, vol. 265, 448-457 (1987); and H. M. Ribeiro et al.,Intl. J. of Cosmetic Science, vol. 26, 47-59 (2004).

X-Ray Analysis Method

Small-angle x-ray scattering (“SAXS”) as used to resolve periodicstructures in mesophases is essentially an x-ray diffraction technique.It is used in conjunction with conventional wide-angle x-ray diffraction(“WXRD”) to characterize aggregate structures such as micelles, gelnetworks, lamella, hexagonal and cubic liquid crystals. The differentmesophases that show periodic structures can be characterized by therelative positions (d-spacing) of their reflections as derived from theBragg equation (d=λ/2Sin θ) where d represents the interplanar spacing,λ the radiation wavelength and θ the scattering (diffraction) angle.

The one dimensional lamella gel network phase is characterized by theratio of the interplanar spacings d₁/d₁, d₁/d₂, d₁/d₃, d₁/d₄, d₁/d₅having the values 1:2:3:4:5 etc. in the SAXS region (long-range order)and one or two invariant reflection(s) in the WXRD region (short-range)centered around 3.5 and 4.5 Å over a broad halo background. Othermesophases (e.g. hexagonal or cubic) will have characteristicallydifferent d-spacing ratios.

WXRD data are collected in transmission mode on a Stoe STADI-Pdiffractometer equipped with an image plate position-sensitive detector.The specimen is positioned between two Mylar films in the sample holderand placed in the path of the x-ray beam. The IP detector has a solidangle of about 120° 2θ and records diffracted x-ray beamssimultaneously. Data are collected and analyzed using the XPOW software.

SAXS data are collected on Rigaku rotating anode generator with a finefocus filament equipped with a HI-STAR 2-dimensional area detector fromBruker-AXS. The setup has an evacuated chamber, which houses thespecimen, conjoined with an evacuated tube leading to the detector toreduce air scatter. The specimen sample holder consists of copper plateswith small rectangular cavities to hold the fluid-like material and alsoallow the transmission of the x-ray beam. The openings to the cavitiesare sealed with kapton windows to provide leak-free environment undervacuum. The 2-D data are azimuthally integrated and reduced to intensityversus scattering vector (q) or its d equivalent by a combination ofGADDS software and in-house software modules implementing knowntechniques on the Igor platform.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

All documents cited in the Detailed Description of the Invention are, inrelevant part, incorporated herein by reference; the citation of anydocument is not to be construed as an admission that it is prior artwith respect to the present invention. To the extent that any meaning ordefinition of a term in this written document conflicts with any meaningor definition of the term in a document incorporated by reference, themeaning or definition assigned to the term in this written documentshall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A process for preparing an oral compositioncomprising the steps of: a) preparing a fatty amphiphile dispersioncomprising the steps of: i) providing a fatty amphiphile having a chainmelt temperature, a dispersing surfactant, and solvent; ii) heatingfatty amphiphile to a temperature sufficient to allow emulsification ofsaid fatty amphiphile to form a fatty amphiphile dispersion with thedispersing surfactant and solvent; and b) adding said fatty amphiphiledispersion to a swelling surfactant to form a gel network, and c) addingoral carrier materials in step a), after step a) in step b) and/or afterstep b).
 2. The process for preparing an oral composition according toclaim 1 wherein a gel network is not formed in the fatty amphiphiledispersion until after said swelling surfactant is added.
 3. A processfor preparing an oral composition according to claim 1 wherein the fattyamphiphile dispersion is cooled below the chain melt temperature of saidfatty amphiphile before it is mixed with the swelling surfactant in stepb).
 4. The process for preparing an oral composition according to claim1 wherein some oral carriers are combined with said fatty amphiphiledispersion prior to adding said swelling surfactant to said fattyamphiphile dispersion.
 5. The process according to claim 1 wherein someoral carriers are added after step a).
 6. The process according to claim1 wherein a suppressing material is added to the fatty amphiphiledispersion.
 7. The process according to claim 1 wherein after said fattyamphiphile dispersion is prepared, no additional heating occurs duringmaking of said oral composition.